On-chip self-calibration of a gyroscope is a valuable feature that can eliminate expensive and time consuming mechanical calibration of the device using rate tables and address any long term drift of its scale factor. In recent years a number of self-test and self-calibration techniques for gyroscopes and accelerometers have appeared in the literature. A common feature to those techniques is the incorporation of a mobile platform of some sort (e.g. a rotary stage) in the sensor die to perform the calibration. With such systems, the gyroscope is physically rotated and the typical readout architecture relies on signal amplitude to measure the rotation rate of the device. With such readout schemes, only one of two resonance modes of the device is electrically excited. The Coriolis force caused by a rotation around the gyroscope axis creates a coupling between the two modes, so that the amplitude of the second resonance mode—which is used as the sense signal—is proportional to the angular velocity of rotation Ωz. Unfortunately, rotary stages add to the complexity and cost of a gyroscope.
Accordingly, a need exists for a system and technique in which a gyroscope, accelerometer, or other device may be self-calibrated without the need to physically rotate the device in order to determine an angular velocity of rotation for calibration purposes.